const toMilliseconds = hour => {
    return hour * 60 * 60 * 1000
}

const leftPad = num => {
    return num < 10 ? '0' : ''
}

const msToString = ms => {
    const minFromMS = ms / 60 / 1000
    const min = Math.round(minFromMS % 60)
    const h = Math.floor(minFromMS / 60)
    return `${leftPad(h)}${h}:${leftPad(min)}${min}`
}

const resetDate = date => {
    date.setHours(0)
    date.setMinutes(0)
    date.setSeconds(0)
    date.setMilliseconds(0)
    return date
}

// starts with sunday
const atomicOpeningTimes = [
    {
        from: 0,
        to: 0,
        nextOpen: toMilliseconds(24) + toMilliseconds(7),
    },
    {
        from: toMilliseconds(7),
        to: toMilliseconds(20),
        nextOpen: toMilliseconds(24) + toMilliseconds(7),
    },
    {
        from: toMilliseconds(7),
        to: toMilliseconds(20),
        nextOpen: toMilliseconds(24) + toMilliseconds(7),
    },
    {
        from: toMilliseconds(7),
        to: toMilliseconds(20),
        nextOpen: toMilliseconds(24) + toMilliseconds(7),
    },
    {
        from: toMilliseconds(7),
        to: toMilliseconds(20),
        nextOpen: toMilliseconds(24) + toMilliseconds(7),
    },
    {
        from: toMilliseconds(7),
        to: toMilliseconds(20),
        nextOpen: toMilliseconds(24) + toMilliseconds(7),
    },
    {
        from: toMilliseconds(7),
        to: toMilliseconds(20),
        nextOpen: toMilliseconds(24) + toMilliseconds(24) + toMilliseconds(7),
    },
]


const checkOpenningTimes = date => {
    const nowInMs = date.getTime()
    const data = atomicOpeningTimes[date.getDay()]

    const morning = resetDate(date)
    const morningInMS = morning.getTime()

    const diff = nowInMs - morningInMS

    // currently closed, opening same day
    if (diff < data.from) {
        return `öffnet in ${msToString(data.from - diff)}`
    }

    // currently open
    if (diff > data.from && diff < data.to) {
        return `noch ${msToString(data.to - diff)} geöffnet`
    }

    // already closed, opening next time
    if(diff > data.to){
        return `zur zeit geschlossen, öffnet wieder in ${msToString(data.nextOpen - diff)}`
    }
    
    return 'wtf...'

}

module.exports = checkOpenningTimes